I am building a new home and they are ready to pour the concrete patio. I have mixed messages about whether the patio should be pinned to the foundation to avoid cracking/settling. We live in NE so the weather brings freeze/thaw. A deck is above the patio and sits on 3 ft deep footings. The concrete patio will be over those footings as well. Should we pin the patio to the foundation or will that cause more cracking than leaving it alone?

Don't pin a patio unless you plan to make it a heated space some day, if so you will still need footings around the edge. I say no.

I agree, don't pin it and just allow it to float. There should be a spacer between the pation and the foundation that creats a slip joint and expansion crack.

Expansion joint and pin it. 3/8 pins 24"oc.

reason is the patio against the house freezes last. The front freezes first. front lifts and put down pressure on area closes to warmer ground by house. This over time can can cause the sloped slab to become flatter and sometimes it starts to develop a puddle by house wall and that keeps the ground softer and sinks more on down pressure. This area is real crucial to maintain when a door is there that swings out and the slab is flush to inside concrete floor, handicap setup. The dirt prep under the slab is very important. Slope the dirt away from the house and mechanically tamp. Now the 4" crushed stone to level the subase for crete. This way the dirt also drains water under slab and puddles won't lay under stone and freeze. Ive ripped out patios since 20 years ago that were fine except the when out of slope from years of the front freezing and the area at the house sinks and water puddles.

The slab will float fine. Make sure you have no less that 1/4 fall away from house. I also short pin Felt expansion joints in walks so when the heave they do it it together and maintain flushness to each other as they move and one block doesn't raise faster and create a trip spot yet it all moves.


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Do not pin the patio to the house. Allow it to float. If you pin and you use expansion, well that's kind of like an oxi moron. The sole purpose of pinning it is to keep it from settling lower than the house and when you pin it you do not allow the pad to move. Proper tamping will keep it from settling so use expansion against the house. It lets the pad move very seldom. Its more likely to crack if you pin it. If you pin it and use expansion, well that just cancels both out, that doesn't make sense to me? When you use expansion be sure to use a Sika Flex caulk against the house above expansion to keep water from getting in between house and pad , which will keep freeze and expand in winter time.

Should a guy pin his broken slab to a new sidewalk?

Yes, I would also vote for not pinning the concrete patio because it would yield no purpose. Let it float, it would be much better option.